32,726 research outputs found

    Modeling and Simulation of Regenerative Braking Energy in DC Electric Rail Systems

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    Regenerative braking energy is the energy produced by a train during deceleration. When a train decelerates, the motors act as generators and produce electricity. This energy can be fed back to the third rail and consumed by other trains accelerating nearby. If there are no nearby trains, this energy is dumped as heat to avoid over voltage. Regenerative braking energy can be saved by installing energy storage systems (ESS) and reused later when it is needed. To find a suitable design, size and placement of energy storage, a good understanding of this energy is required. The aim of this paper is to model and simulate regenerative braking energy. The dc electric rail transit system model introduced in this paper includes trains, substations and rail systems

    Conformal mapping of unbounded multiply connected regions onto canonical slit regions

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    We present a boundary integral equation method for conformal mapping of unbounded multiply connected regions onto five types of canonical slit regions. For each canonical region, three linear boundary integral equations are constructed from a boundary relationship satisfied by an analytic function on an unboundedmultiply connected region. The integral equations are uniquely solvable. The kernels involved in these integral equations are the modified Neumann kernels and the adjoint generalized Neumann kernels

    Mass Rearing of the Greater Wax Moth, \u3ci\u3eGalleria Mellonella\u3c/i\u3e (Lepidoptera: Pyralidae), for Small-Scale Laboratory Studies

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    A technique was developed to mass rear the greater wax moth, Galleria mellonella, economically (ca. 0.2 cents per larva exclusive of 3-5 h of labor costs per week). Mortality in the egg and early larval stages was ca. 48% whereas in later larval and pupal stages it was ca. 10% and 27% respectively. With a fecundity of 650-1120 eggs per female, and notwithstanding the high egg and early larval mortality, the procedure easily provides a self-sustaining culture with high yields of all stages

    Sacrococcygeal teratoma excision: a vertical rather than transverse wound closure

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    Background: The chevron incision has been the standard approach for sacrococcygeal teratoma (SCT) excision. Here, we are reporting our experience of shifting to the vertical posterior sagittal approach.Patients and methods: During the period 2011 through 2016, we operated on 17 (16 female and one male) cases of SCT. Their age at presentation ranged from day 1 to 26 months (mean=4.8 months, median=2 months). The chevron incision was used in five, whereas the vertical posterior sagittal approach was used in 12 patients.Results: In this series, we had one case of perioperative mortality, in addition to another case of perineal wound disruption (in the group of vertical wound closure), which was managed conservatively (to heal by secondary intention) with a very satisfactory hidden scar at 6-month follow-up. Overall, we did not find the vertical approach to add any extra limitations to the surgical exposure or dissection; meanwhile, it provided a well-recognized cosmetic advantage.Conclusion: The vertical posterior sagittal approach for excision of SCT is both feasible and advantageous in terms of the cosmetic outcome. It provides a well-hidden scar in the natal cleft and preserves normal contouring of the buttocks.Keywords: buttock, cosmesis, posterior sagittal, reconstruction, sacrococcygeal teratom

    Effect of Stretching Versus Aerobic Exercises on Pregnant Diabetic Women

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    Purpose: This study was conducted to determine the effect of stretching versus aerobic exercises on pregnant diabetic women. Subjects: Sixty primigravidae and multigravidae women shared in this study. They were selected from Benha University Hospital in Benha. Their ages were ranged from 25-35 years. Their BMI was ranged from 30-35 kg/m2. Their gestational ages were between 20-24 weeks’ gestation. All pregnant women were complaining of gestational diabetes mellitus. Design: Design of this study was randomized controlled study. They were randomly assigned into two equal groups: Group A (stretching exercises group); It consisted of thirty pregnant diabetic women. They were treated by medical treatment, diet control and stretching exercises for 40 minutes, 3 times per week, after one hour of the main meal and insulin injection, for 12 weeks. Group B (aerobic exercises group); It consisted of thirty pregnant diabetic women. They were treated by medical treatment, diet control and aerobic exercise program in the form of walking on treadmill, at moderate intensity (60% of the maximum heart rate), for 45 minutes, 3 times per week, after one hour of the main meal and insulin injection, for 12 weeks. Methods: Body mass index (BMI) was assessed by weight and height scale. Fasting and postprandial blood glucose levels were assessed by using blood glucose monitoring system; fasting insulin level and HbA1C were assessed by blood analysis for each woman in both groups A and B before and after treatment. Results: Results of this study revealed that there was significant decrease in fasting blood glucose level, post-prandial blood glucose level, fasting insulin level and HbA1C level in both groups A and B after treatment. Pretreatment, there was no significant difference between both groups A and B in fasting blood glucose level, post-prandial blood glucose level, fasting insulin level and HbA1C level. Post treatment, there was significant difference between both groups A and B in fasting blood glucose level, post-prandial blood glucose level, fasting insulin level and HbA1C level (more decrease in group A). Conclusion: It can be concluded that both stretching and aerobic exercises during pregnancy can improve gestational diabetes mellitus by decreasing fasting blood glucose level, post-prandial blood glucose level, fasting insulin level and HbA1C level, but stretching exercises are more effective than aerobic exercises

    New Benzoxazole Derivatives as Antiprotozoal Agents: In Silico Studies, Synthesis, and Biological Evaluation

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    Background. Benzoxazole derivatives have different biological activities. In pursuit of designing novel chemical entities with antiprotozoal and antimicrobial activities, benzoxazolyl aniline was utilized as a privileged scaffold of a series of (3-benzoxazole-2-yl) phenylamine derivatives, 3-benzoxazoloyl acetamide, and butyramide derivatives. Methods. These novel analogs were synthesized in straightforward simple chemistry without any quantitative chromatographic separations in reasonable yields. The biological evaluation of all target compounds as potential antimalarial, antileishmanial, antitrypanosomal, and antimicrobial agents was performed by various well-established cell-based methods. Results. Compounds 6d and 5a showed promising biological screening data. The amidation of 3-benzoxazolyl aniline 1 with the chloroacetyl functional group resulted in a good antimalarial activity and showed moderate inhibitory activities against leishmanial and trypanosomal spp. Moreover, chloroacetyl functionalization of benzoxazolyl aniline serves as a good early goal for constructing and synthesizing new antimicrobial and antiprotozoal agents. The molecular docking study rationalizes the relative inhibitory activity of compound 5a as an antimalarial agent with the deregulation of PfPNP activity which has emerged as a major mechanism of these targets
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